1. Field of the Invention
The invention pertains to a squirrel-cage rotor having closed grooves extending along the circumference of the rotor, in which a squirrel cage rotor, with closed grooves extending along the circumference of the rotor, in which grooves, via the introduction of aluminum, aluminum conductor rods are produced, with the conductor rods filling out the grooves, wherein the groove cross section includes noses that extend into ideally-deemed groove cross sections, and bulges extend from the ideally-deemed groove cross sections.
2. Discussion of the Background of the Invention and Material Information
Asynchronous machines, with squirrel-cage rotors, due to their great advantages, such as, for example, low acquisition costs and low operating costs, ready adaptability to a large number of differing machines, as well as low maintenance, enjoy a broad distribution. These are usable in those instances having only low requirements relative to revolution, stability and speed range. In the start up phase generally no additional actuators are required.
In rotors having aluminum-compression or centrifugally cast squirrel-cages in the revolution range over 6000Rpm, it is a common occurrence that the rotors become imbalanced due to the shifting or displacement of the conductor rods in their grooves. Such shifts or displacements of the conductor rods already occurs either during the cooling of the aluminum, due to the considerable shrinkage thereof, or during high speed operation.
German Patent Publication DE, B, 1 190 094 describes an attachment of rods in the squirrel-cage rotor of electrical machines, in which embossed noses are provided on the rods, which fit into corresponding recesses in the rod grooves.
U.S. Pat. No. 2,350,012 describes a rotor having closed grooves which includes noses that extend into the groove thereby significantly varying the tooth width between the grooves.
It is the task of the invention to produce, with simple means, a squirrel-cage rotor whose conductor rods are so fixed in place that, even at very high speed operation, no imbalance can occur.